Polar reactions of acyclic conjugated bisallenes

• Reiner Stamm and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 36–48, doi:10.3762/bjoc.9.5

• ) accounts for our experimental observations. Regardless of the exact structures of the silylation products 21, we did not observe any selectivity in this transformation. Quenching of 4 with N,N-dimethylformamide (DMF) and acetone Metalated allenes are known to be converted into allenic aldehydes on DMF

Influence of cyclodextrin on the solubility and the polymerization of (meth)acrylated Triton^® X-100

• Melanie Kemnitz and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 2176–2183, doi:10.3762/bjoc.8.245

• orientation of the CD ring could be drawn. An interaction between CD and the (meth)acrylic group could not be detected. In the course of DLS experiments with dimethylformamide (DMF) as solvent a hydrodynamic diameter of 1.4 nm for pure RAMEB-CD and 1.2 nm for 3 was found. For each complexed RAMEB-CD the

Cyclodextrin-induced host–guest effects of classically prepared poly(NIPAM) bearing azo-dye end groups

• Gero Maatz,
• Arkadius Maciollek and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 1929–1935, doi:10.3762/bjoc.8.224

• purification. RAMEB-CD and β-CD were obtained from Wacker Chemie GmbH, Burghausen, Germany and were used after being dried overnight with a vacuum oil pump over P4O10. N,N-Dimethylformamide (DMF) was purchased from Fluka, Germany. Dimethylsulfoxide-d6 (99.9 atom % D) and deuterium oxide, D2O were obtained from

Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery

• Jan Hoyer,
• Ulrich Schatzschneider,
• Michaela Schulz-Siegmund and
• Ines Neundorf

Beilstein J. Org. Chem. 2012, 8, 1788–1797, doi:10.3762/bjoc.8.204

• acid, trypan blue, 5(6)-carboxyfluorescein (CF) and 2,2,2-trifluoroethanol were purchased from Fluka (Taufkirchen, Germany). Chlorambucil (Cbl) and the resazurin-based in vitro toxicology assay kit were purchased from Sigma-Aldrich (Taufkirchen, Germany). N,N-Dimethylformamide (DMF), dichloromethane

Polysiloxane ionic liquids as good solvents for β-cyclodextrin-polydimethylsiloxane polyrotaxane structures

• Narcisa Marangoci,
• Rodinel Ardeleanu,
• Laura Ursu,
• Constanta Ibanescu,
• Maricel Danu,
• Mariana Pinteala and
• Bogdan C. Simionescu

Beilstein J. Org. Chem. 2012, 8, 1610–1618, doi:10.3762/bjoc.8.184

• of β-CD-polydimethylsiloxane polyrotaxane (PRot) was carried out according to a method previously described [17][22] and the compound was obtained as a white powder (approximately 55% yield). PRot was prepared by mixing β-CD in dimethylformamide (DMF, saturated solution) with α,ω-bis(3

Regioselective synthesis of 7,8-dihydroimidazo[5,1-c][1,2,4]triazine-3,6(2H,4H)-dione derivatives: A new drug-like heterocyclic scaffold

• Nikolay T. Tzvetkov,
• Harald Euler and
• Christa E. Müller

Beilstein J. Org. Chem. 2012, 8, 1584–1593, doi:10.3762/bjoc.8.181

• alkylation reagent and potassium carbonate as a base in dry dimethylformamide (DMF) were used. The best yield (92%) was achieved with ethyl 2-bromopropionate and benzyl bromide as alkylating reagents. Although this procedure led to the direct formation of the desired N3-substituted products, the

• -position of 5,5-dimethylhydantoin (6). The subsequent N1-alkylation of 2,5-dioxoimidazolidines 7–10 to the corresponding N,N-disubstituted hydantoins 12–18 was performed with 1.0–1.2 equiv of the appropriate alkylating reagent by using sodium hydride as a base in dry dimethylformamide (DMF) (Table 2

Interaction of cyclodextrins with pyrene-modified polyacrylamide in a mixed solvent of water and dimethyl sulfoxide as studied by steady-state fluorescence

• Akihito Hashidzume,
• Yongtai Zheng and
• Akira Harada

Beilstein J. Org. Chem. 2012, 8, 1312–1317, doi:10.3762/bjoc.8.150

• -Dimethylformamide (DMF) and dichloromethane (DCM) were purified by utilizing a glass contour solvent dispensing system. Water was purified by a Millipore Milli-Q system. β-CD and γ-CD were purchased from Junsei Chemical Co. Ltd. and recrystallized twice from water before use. N-1-Pyrenylmethylacrylamide (APy) was

Synthesis and characterization of a novel carboxyl group containing (co)polyimide with sulfur in the polymer backbone

• Miroslav Mrsevic,
• David Düsselberg and
• Claudia Staudt

Beilstein J. Org. Chem. 2012, 8, 776–786, doi:10.3762/bjoc.8.88

• solubility in amidic solvents, such as dimethylacetamide (DMAC), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP), as well as in other non-amidic solvents, such as tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and acetone. No differences in solubility either between the different (co)polyimides

Investigation of the network of preferred interactions in an artificial coiled-coil association using the peptide array technique

• Raheleh Rezaei Araghi,
• Carsten C. Mahrenholz,
• Rudolf Volkmer and
• Beate Koksch

Beilstein J. Org. Chem. 2012, 8, 640–649, doi:10.3762/bjoc.8.71

• . In the second coupling step, the anchor position Fmoc-β-alanine-OPfp in dimethylsulfoxide (DMSO) was used. Residual amino functions between the spots were capped by acetylation. The Fmoc group was cleaved by using 20% piperidine in dimethylformamide (DMF). The cellulose-bound peptide arrays were

Synthesis of szentiamide, a depsipeptide from entomopathogenic Xenorhabdus szentirmaii with activity against Plasmodium falciparum

• Friederike I. Nollmann,
• Andrea Dowling,
• Marcel Kaiser,
• Klaus Deckmann,
• Sabine Grösch,
• Richard ffrench-Constant and
• Helge B. Bode

Beilstein J. Org. Chem. 2012, 8, 528–533, doi:10.3762/bjoc.8.60

• hexafluorophosphate (HBTU) in dimethylformamide (DMF) and N,N-diisopropylethylamine (DIEA) in N-methylpyrrolidone (NMP), assisted by microwave irradiation. After the final Fmoc-deprotection with 20% piperidine in DMF, the N-terminus was formylated with para-nitrophenyl formate (pNPF) in the presence of N

• /Carbolution Chemicals; c = 0.2 mol/L) was activated in situ with 5 equiv O-benzotriazole-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU; Iris Biotech) in dimethylformamide (DMF; Acros Organics, Belgium; c = 0.5 mol/L) in the presence of 10 equiv N,N-diisopropylethylamine (DIEA; Novabiochem, Darmstadt

Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

• Nina Gonsior,
• Fabian Mohr and
• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 390–397, doi:10.3762/bjoc.8.42

• column set up with one Viscotek TSK guard column HHR-H 6.0 mm (ID)_4 cm (L) and two Viscotek TSK GMHHR-M 7.8 mm (ID)_30 cm (L) columns at 60 °C. N,N-Dimethylformamide (DMF, 0.1 M LiCl) was used as eluent at a flow rate of 1 mL min−1. A Viscotek VE 3500 RI detector and a Viscotek Viscometer model 250 were

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• ampicillin (30 µg mL−1) as the standard antibiotic reference for antibacterial activity, and calforan (30 µg mL−1) was used as a reference antifungal activity. The tested compounds were dissolved in N,N-dimethylformamide (DMF) to give a solution of 1 mg mL−1. The inhibition zones (diameter of the hole) were

Studies on Pd/NiFe₂O₄ catalyzed ligand-free Suzuki reaction in aqueous phase: synthesis of biaryls, terphenyls and polyaryls

• Sanjay R. Borhade and
• Suresh B. Waghmode

Beilstein J. Org. Chem. 2011, 7, 310–319, doi:10.3762/bjoc.7.41

• Suzuki coupling reaction (Table 1). These results indicated that the reaction in polar aprotic solvents such as dimethylformamide (DMF), dimethylacetamide (DMA), N-methylpyrrolidin-2-one (NMP) and dimethylsulfoxide (DMSO) showed only 34–50% conversion after 2 h (Table 1, entries 1–4). The reaction in

Chiral recognition of macromolecules with cyclodextrins: pH- and thermosensitive copolymers from N-isopropylacrylamide and N-acryloyl-D/L-phenylalanine and their inclusion complexes with cyclodextrins

• Sabrina Gingter,
• Ella Bezdushna and
• Helmut Ritter

Beilstein J. Org. Chem. 2011, 7, 204–209, doi:10.3762/bjoc.7.27

• chloride (97%) and N-isopropylacrylamide (NIPAAm, 97%) were obtained from Aldrich, Germany, and used as received. Azobisisobutyronitrile (AIBN) (96%) and N,N-dimethylformamide (DMF) were purchased from Fluka, Germany. Dimethylsulfoxide-d6 (99.9 atom % D) and deuterium oxide D2O were obtained from Deutero

• Viscotek TSK GMHHR-M 7.8 mm (ID) × 30 cm (L) columns at 60 °C. N,N-Dimethylformamide (DMF, 0.1 M LiCl) was used as eluent at a flow rate of 1 mL·min−1. A Viscotek VE 3500 RI detector and a Viscotek Viscometer model 250 were used. The system was calibrated with polystyrene standards with a molecular range

Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone

• Julia Theis and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 938–944, doi:10.3762/bjoc.6.105

• 1 186 000 Da. Dynamic light scattering (DLS) experiments were implemented on a Malvern HPPS-ET apparatus at a temperature of 25 °C using dimethylformamide (DMF) as solvent. Hellma Suprasil precision cells (110-QS) were used. The particle size distribution was derived from a deconvolution of the

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• freshly distilled before use. Dimethylformamide (DMF) was distilled over calcium hydride. All other chemicals were used as received. Characterization NMR spectra were recorded on a Bruker NMR spectrometer DRX500. Elemental analysis was done with a Hekatech EA 3000 Euro Vector CHNSO Elementaranalysator

Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

• Bernd Garska,
• Monir Tabatabai and
• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, 784–788, doi:10.3762/bjoc.6.83

• AppliChem (Germany). N,N-Dimethylformamide (DMF) and sodium hydroxide (NaOH) were purchased from VWR (USA). Dimethylsulfoxide-d6 99.9% atom% D was obtained from Deutero GmbH (Germany). Commercially available reagents and solvents were used without further purification. calix[4]arene 1 [19], calix[4]arene

Versatile supramolecular reactivity of zinc-tetra(4-pyridyl)porphyrin in crystalline solids: Polymeric grids with zinc dichloride and hydrogen-bonded networks with mellitic acid

• Sophia Lipstman and
• Israel Goldberg

Beilstein J. Org. Chem. 2009, 5, No. 77, doi:10.3762/bjoc.5.77

• , ethanol, and N,N-dimethylformamide (DMF). The resulting solution was refluxed for 16 h, and then cooled to room temperature and left for crystallization. X-ray quality crystals were obtained after four days. It appeared in both cases that ZnCl2 was formed in situ under the acidic conditions by extracting

The efficient synthesis of dibenzo[d,d′]benzo[1,2-b:4,3-b′]dithiophene and cyclopenta[1,2-b:4,3-b′]bis(benzo[d]thiophen)-6-one

• Zhihua Wang,
• Sheng Zhu,
• Jianwu Shi and
• Hua Wang

Beilstein J. Org. Chem. 2009, 5, No. 55, doi:10.3762/bjoc.5.55

• starting material, formylation and McMurry reaction were employed for preparing 1. The formylation step involves sequential deprotonation of 3 and treatment of the intermediate dilithiated species with N,N-dimethylformamide (DMF). Attempted generation of dilithiated 3 with either lithium diisopropylamide

A practical synthesis of the ¹³C/¹⁵N- labelled tripeptide N-formyl- Met-Leu-Phe, useful as a reference in solid- state NMR spectroscopy

• Sven T. Breitung,
• Jakob J. Lopez,
• Gerd Dürner,
• Clemens Glaubitz,
• Michael W. Göbel and
• Marcel Suhartono

Beilstein J. Org. Chem. 2008, 4, No. 35, doi:10.3762/bjoc.4.35

• .) Coupling of further building blocks: In case of quantitative conversion, the resin was washed with N,N-dimethylformamide (DMF, 5 ×) and treated three times (15 min, 10 min, 5 min) with a piperidine solution (25% in DMF). Then the resin was washed with N-methylpyrrolidone (NMP, 5 ×) and a solution of 13C

Ru-catalyzed dehydrogenative coupling of carboxylic acids and silanes - a new method for the preparation of silyl ester

• Guo-Bin Liu and
• Hong-Yun Zhao

Beilstein J. Org. Chem. 2008, 4, No. 27, doi:10.3762/bjoc.4.27

• detected (12–22%) (Table 2, Runs 2–8). In N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMAc), the dehydrocoupling failed to reach completion being heated at 100 °C for 48 h, and significant amounts of Et3SiH were detected (Table 2, Runs 9 and 10). Other Ru complexes were also tested as catalysts

Colchitaxel, a coupled compound made from microtubule inhibitors colchicine and paclitaxel

• Karunananda Bombuwala,
• Thomas Kinstle,
• Vladimir Popik,
• Sonal O. Uppal,
• James B. Olesen,
• Jose Viña and
• Carol A. Heckman

Beilstein J. Org. Chem. 2006, 2, No. 13, doi:10.1186/1860-5397-2-13

• , DMAP, Et3N; b) MeONa at 0°C; c) TFA; d) glutaric anhydride, dimethylformamide (DMF) Reagents and conditions for protection of paclitaxel and coupling to N-glutaryl-deacetylcolchicine (6). The reagents used at each step are: a) TBDMSCl, DMAP; b) DCC, DMAP; c) TBAF. Comparison of the logP values